Allison M Cleymaet1, Ann M Hess2, Kate S Freeman1. 1. Department of Clinical Sciences, College of Veterinary Medicine, Colorado State University, Veterinary Teaching Hospital, 300 West Drake Road, Fort Collins, CO, 80523, USA. 2. Department of Statistics, College of Natural Sciences, Colorado State University, Veterinary Teaching Hospital, 300 West Drake Road, Fort Collins, CO, 80523, USA.
Abstract
OBJECTIVES: To measure the central corneal thickness (CCT) in healthy feline eyes with Scheimpflug imaging (Pentacam, Pentacam(®) -HR) and to compare these values with those obtained with spectral-domain optical coherence tomography (OCT, Optovue(®) iVue). ANIMALS STUDIED: Thirty one sedated Domestic Short-haired cats. PROCEDURES: Two repeated CCT measurements were obtained from both eyes using Pentacam measured at the pupil center and corneal apex (CCTpupil and CCTapex ) and using SD-OCT (CCTOCT ). Agreement between the imaging modalities for CCT and intradevice repeatability was evaluated with Bland-Altman analysis. Mixed modeling was used to test for a difference between methods. RESULTS: The calculated mean ± SD CCT was CCTOCT = 584.93 ± 39.05 μm, CCTpupil = 608.25 ± 47.26 μm, and CCTapex = 606.41 ± 44.18 μm. There was a statistically significant difference between CCTOCT vs. CCTpupil (P < 0.0007) and CCTOCT vs. CCTapex (P < 0.0003) (n = 59 eyes). The 95% limits of agreement (LoA) for CCTOCT vs. CCTpupil was (-89.57 μm, 40.04 μm) and for CCTOCT vs. CCTapex was (-79.62 μm, 33.79 μm) (n = 59 eyes). 95% LoA between repeated CCT measurements by SD-OCT was (-10.23 μm, 9.32 μm) and by Pentacam was (-22.66 μm, 18.30 μm) at pupil and (-15.81 μm, 16.17 μm) at corneal apex (n = 11 eyes). CONCLUSIONS: SD-OCT and Pentacam provide excellent CCT measurement repeatability. Pentacamapex is our recommended clinical setting for use of the Pentacam. The level of agreement between SD-OCT and Pentacam for CCT is good.
OBJECTIVES: To measure the central corneal thickness (CCT) in healthy feline eyes with Scheimpflug imaging (Pentacam, Pentacam(®) -HR) and to compare these values with those obtained with spectral-domain optical coherence tomography (OCT, Optovue(®) iVue). ANIMALS STUDIED: Thirty one sedated Domestic Short-haired cats. PROCEDURES: Two repeated CCT measurements were obtained from both eyes using Pentacam measured at the pupil center and corneal apex (CCTpupil and CCTapex ) and using SD-OCT (CCTOCT ). Agreement between the imaging modalities for CCT and intradevice repeatability was evaluated with Bland-Altman analysis. Mixed modeling was used to test for a difference between methods. RESULTS: The calculated mean ± SD CCT was CCTOCT = 584.93 ± 39.05 μm, CCTpupil = 608.25 ± 47.26 μm, and CCTapex = 606.41 ± 44.18 μm. There was a statistically significant difference between CCTOCT vs. CCTpupil (P < 0.0007) and CCTOCT vs. CCTapex (P < 0.0003) (n = 59 eyes). The 95% limits of agreement (LoA) for CCTOCT vs. CCTpupil was (-89.57 μm, 40.04 μm) and for CCTOCT vs. CCTapex was (-79.62 μm, 33.79 μm) (n = 59 eyes). 95% LoA between repeated CCT measurements by SD-OCT was (-10.23 μm, 9.32 μm) and by Pentacam was (-22.66 μm, 18.30 μm) at pupil and (-15.81 μm, 16.17 μm) at corneal apex (n = 11 eyes). CONCLUSIONS:SD-OCT and Pentacam provide excellent CCT measurement repeatability. Pentacamapex is our recommended clinical setting for use of the Pentacam. The level of agreement between SD-OCT and Pentacam for CCT is good.